drivers/hwmon/dell-smm-hwmon.c

   1 /*
   2  * dell-smm-hwmon.c -- Linux driver for accessing the SMM BIOS on Dell laptops.
   3  *
   4  * Copyright (C) 2001  Massimo Dal Zotto <dz@debian.org>
   5  *
   6  * Hwmon integration:
   7  * Copyright (C) 2011  Jean Delvare <jdelvare@suse.de>
   8  * Copyright (C) 2013, 2014  Guenter Roeck <linux@roeck-us.net>
   9  * Copyright (C) 2014, 2015  Pali Rohár <pali.rohar@gmail.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU General Public License as published by the
  13  * Free Software Foundation; either version 2, or (at your option) any
  14  * later version.
  15  *
  16  * This program is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  */
  21
  22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  23
  24 #include <linux/delay.h>
  25 #include <linux/module.h>
  26 #include <linux/types.h>
  27 #include <linux/init.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/seq_file.h>
  30 #include <linux/dmi.h>
  31 #include <linux/capability.h>
  32 #include <linux/mutex.h>
  33 #include <linux/hwmon.h>
  34 #include <linux/hwmon-sysfs.h>
  35 #include <linux/uaccess.h>
  36 #include <linux/io.h>
  37 #include <linux/sched.h>
  38
  39 #include <linux/i8k.h>
  40
  41 #define I8K_SMM_FN_STATUS       0x0025
  42 #define I8K_SMM_POWER_STATUS    0x0069
  43 #define I8K_SMM_SET_FAN         0x01a3
  44 #define I8K_SMM_GET_FAN         0x00a3
  45 #define I8K_SMM_GET_SPEED       0x02a3
  46 #define I8K_SMM_GET_FAN_TYPE    0x03a3
  47 #define I8K_SMM_GET_NOM_SPEED   0x04a3
  48 #define I8K_SMM_GET_TEMP        0x10a3
  49 #define I8K_SMM_GET_TEMP_TYPE   0x11a3
  50 #define I8K_SMM_GET_DELL_SIG1   0xfea3
  51 #define I8K_SMM_GET_DELL_SIG2   0xffa3
  52
  53 #define I8K_FAN_MULT            30
  54 #define I8K_FAN_MAX_RPM         30000
  55 #define I8K_MAX_TEMP            127
  56
  57 #define I8K_FN_NONE             0x00
  58 #define I8K_FN_UP               0x01
  59 #define I8K_FN_DOWN             0x02
  60 #define I8K_FN_MUTE             0x04
  61 #define I8K_FN_MASK             0x07
  62 #define I8K_FN_SHIFT            8
  63
  64 #define I8K_POWER_AC            0x05
  65 #define I8K_POWER_BATTERY       0x01
  66
  67 static DEFINE_MUTEX(i8k_mutex);
  68 static char bios_version[4];
  69 static struct device *i8k_hwmon_dev;
  70 static u32 i8k_hwmon_flags;
  71 static uint i8k_fan_mult = I8K_FAN_MULT;
  72 static uint i8k_pwm_mult;
  73 static uint i8k_fan_max = I8K_FAN_HIGH;
  74
  75 #define I8K_HWMON_HAVE_TEMP1    (1 << 0)
  76 #define I8K_HWMON_HAVE_TEMP2    (1 << 1)
  77 #define I8K_HWMON_HAVE_TEMP3    (1 << 2)
  78 #define I8K_HWMON_HAVE_TEMP4    (1 << 3)
  79 #define I8K_HWMON_HAVE_FAN1     (1 << 4)
  80 #define I8K_HWMON_HAVE_FAN2     (1 << 5)
  81
  82 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
  83 MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
  84 MODULE_DESCRIPTION("Dell laptop SMM BIOS hwmon driver");
  85 MODULE_LICENSE("GPL");
  86 MODULE_ALIAS("i8k");
  87
  88 static bool force;
  89 module_param(force, bool, 0);
  90 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
  91
  92 static bool ignore_dmi;
  93 module_param(ignore_dmi, bool, 0);
  94 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
  95
  96 #if IS_ENABLED(CONFIG_I8K)
  97 static bool restricted;
  98 module_param(restricted, bool, 0);
  99 MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
 100
 101 static bool power_status;
 102 module_param(power_status, bool, 0600);
 103 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
 104 #endif
 105
 106 static uint fan_mult;
 107 module_param(fan_mult, uint, 0);
 108 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)");
 109
 110 static uint fan_max;
 111 module_param(fan_max, uint, 0);
 112 MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");
 113
 114 struct smm_regs {
 115         unsigned int eax;
 116         unsigned int ebx __packed;
 117         unsigned int ecx __packed;
 118         unsigned int edx __packed;
 119         unsigned int esi __packed;
 120         unsigned int edi __packed;
 121 };
 122
 123 static inline const char *i8k_get_dmi_data(int field)
 124 {
 125         const char *dmi_data = dmi_get_system_info(field);
 126
 127         return dmi_data && *dmi_data ? dmi_data : "?";
 128 }
 129
 130 /*
 131  * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
 132  */
 133 static int i8k_smm(struct smm_regs *regs)
 134 {
 135         int rc;
 136         int eax = regs->eax;
 137         cpumask_var_t old_mask;
 138
 139         /* SMM requires CPU 0 */
 140         if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
 141                 return -ENOMEM;
 142         cpumask_copy(old_mask, &current->cpus_allowed);
 143         rc = set_cpus_allowed_ptr(current, cpumask_of(0));
 144         if (rc)
 145                 goto out;
 146         if (smp_processor_id() != 0) {
 147                 rc = -EBUSY;
 148                 goto out;
 149         }
 150
 151 #if defined(CONFIG_X86_64)
 152         asm volatile("pushq %%rax\n\t"
 153                 "movl 0(%%rax),%%edx\n\t"
 154                 "pushq %%rdx\n\t"
 155                 "movl 4(%%rax),%%ebx\n\t"
 156                 "movl 8(%%rax),%%ecx\n\t"
 157                 "movl 12(%%rax),%%edx\n\t"
 158                 "movl 16(%%rax),%%esi\n\t"
 159                 "movl 20(%%rax),%%edi\n\t"
 160                 "popq %%rax\n\t"
 161                 "out %%al,$0xb2\n\t"
 162                 "out %%al,$0x84\n\t"
 163                 "xchgq %%rax,(%%rsp)\n\t"
 164                 "movl %%ebx,4(%%rax)\n\t"
 165                 "movl %%ecx,8(%%rax)\n\t"
 166                 "movl %%edx,12(%%rax)\n\t"
 167                 "movl %%esi,16(%%rax)\n\t"
 168                 "movl %%edi,20(%%rax)\n\t"
 169                 "popq %%rdx\n\t"
 170                 "movl %%edx,0(%%rax)\n\t"
 171                 "pushfq\n\t"
 172                 "popq %%rax\n\t"
 173                 "andl $1,%%eax\n"
 174                 : "=a"(rc)
 175                 :    "a"(regs)
 176                 :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 177 #else
 178         asm volatile("pushl %%eax\n\t"
 179             "movl 0(%%eax),%%edx\n\t"
 180             "push %%edx\n\t"
 181             "movl 4(%%eax),%%ebx\n\t"
 182             "movl 8(%%eax),%%ecx\n\t"
 183             "movl 12(%%eax),%%edx\n\t"
 184             "movl 16(%%eax),%%esi\n\t"
 185             "movl 20(%%eax),%%edi\n\t"
 186             "popl %%eax\n\t"
 187             "out %%al,$0xb2\n\t"
 188             "out %%al,$0x84\n\t"
 189             "xchgl %%eax,(%%esp)\n\t"
 190             "movl %%ebx,4(%%eax)\n\t"
 191             "movl %%ecx,8(%%eax)\n\t"
 192             "movl %%edx,12(%%eax)\n\t"
 193             "movl %%esi,16(%%eax)\n\t"
 194             "movl %%edi,20(%%eax)\n\t"
 195             "popl %%edx\n\t"
 196             "movl %%edx,0(%%eax)\n\t"
 197             "lahf\n\t"
 198             "shrl $8,%%eax\n\t"
 199             "andl $1,%%eax\n"
 200             : "=a"(rc)
 201             :    "a"(regs)
 202             :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 203 #endif
 204         if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
 205                 rc = -EINVAL;
 206
 207 out:
 208         set_cpus_allowed_ptr(current, old_mask);
 209         free_cpumask_var(old_mask);
 210         return rc;
 211 }
 212
 213 /*
 214  * Read the fan status.
 215  */
 216 static int i8k_get_fan_status(int fan)
 217 {
 218         struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
 219
 220         regs.ebx = fan & 0xff;
 221         return i8k_smm(&regs) ? : regs.eax & 0xff;
 222 }
 223
 224 /*
 225  * Read the fan speed in RPM.
 226  */
 227 static int i8k_get_fan_speed(int fan)
 228 {
 229         struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
 230
 231         regs.ebx = fan & 0xff;
 232         return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
 233 }
 234
 235 /*
 236  * Read the fan type.
 237  */
 238 static int i8k_get_fan_type(int fan)
 239 {
 240         struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
 241
 242         regs.ebx = fan & 0xff;
 243         return i8k_smm(&regs) ? : regs.eax & 0xff;
 244 }
 245
 246 /*
 247  * Read the fan nominal rpm for specific fan speed.
 248  */
 249 static int i8k_get_fan_nominal_speed(int fan, int speed)
 250 {
 251         struct smm_regs regs = { .eax = I8K_SMM_GET_NOM_SPEED, };
 252
 253         regs.ebx = (fan & 0xff) | (speed << 8);
 254         return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
 255 }
 256
 257 /*
 258  * Set the fan speed (off, low, high). Returns the new fan status.
 259  */
 260 static int i8k_set_fan(int fan, int speed)
 261 {
 262         struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
 263
 264         speed = (speed < 0) ? 0 : ((speed > i8k_fan_max) ? i8k_fan_max : speed);
 265         regs.ebx = (fan & 0xff) | (speed << 8);
 266
 267         return i8k_smm(&regs) ? : i8k_get_fan_status(fan);
 268 }
 269
 270 static int i8k_get_temp_type(int sensor)
 271 {
 272         struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP_TYPE, };
 273
 274         regs.ebx = sensor & 0xff;
 275         return i8k_smm(&regs) ? : regs.eax & 0xff;
 276 }
 277
 278 /*
 279  * Read the cpu temperature.
 280  */
 281 static int _i8k_get_temp(int sensor)
 282 {
 283         struct smm_regs regs = {
 284                 .eax = I8K_SMM_GET_TEMP,
 285                 .ebx = sensor & 0xff,
 286         };
 287
 288         return i8k_smm(&regs) ? : regs.eax & 0xff;
 289 }
 290
 291 static int i8k_get_temp(int sensor)
 292 {
 293         int temp = _i8k_get_temp(sensor);
 294
 295         /*
 296          * Sometimes the temperature sensor returns 0x99, which is out of range.
 297          * In this case we retry (once) before returning an error.
 298          # 1003655137 00000058 00005a4b
 299          # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
 300          # 1003655139 00000054 00005c52
 301          */
 302         if (temp == 0x99) {
 303                 msleep(100);
 304                 temp = _i8k_get_temp(sensor);
 305         }
 306         /*
 307          * Return -ENODATA for all invalid temperatures.
 308          *
 309          * Known instances are the 0x99 value as seen above as well as
 310          * 0xc1 (193), which may be returned when trying to read the GPU
 311          * temperature if the system supports a GPU and it is currently
 312          * turned off.
 313          */
 314         if (temp > I8K_MAX_TEMP)
 315                 return -ENODATA;
 316
 317         return temp;
 318 }
 319
 320 static int i8k_get_dell_signature(int req_fn)
 321 {
 322         struct smm_regs regs = { .eax = req_fn, };
 323         int rc;
 324
 325         rc = i8k_smm(&regs);
 326         if (rc < 0)
 327                 return rc;
 328
 329         return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
 330 }
 331
 332 #if IS_ENABLED(CONFIG_I8K)
 333
 334 /*
 335  * Read the Fn key status.
 336  */
 337 static int i8k_get_fn_status(void)
 338 {
 339         struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
 340         int rc;
 341
 342         rc = i8k_smm(&regs);
 343         if (rc < 0)
 344                 return rc;
 345
 346         switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
 347         case I8K_FN_UP:
 348                 return I8K_VOL_UP;
 349         case I8K_FN_DOWN:
 350                 return I8K_VOL_DOWN;
 351         case I8K_FN_MUTE:
 352                 return I8K_VOL_MUTE;
 353         default:
 354                 return 0;
 355         }
 356 }
 357
 358 /*
 359  * Read the power status.
 360  */
 361 static int i8k_get_power_status(void)
 362 {
 363         struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
 364         int rc;
 365
 366         rc = i8k_smm(&regs);
 367         if (rc < 0)
 368                 return rc;
 369
 370         return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
 371 }
 372
 373 /*
 374  * Procfs interface
 375  */
 376
 377 static int
 378 i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
 379 {
 380         int val = 0;
 381         int speed;
 382         unsigned char buff[16];
 383         int __user *argp = (int __user *)arg;
 384
 385         if (!argp)
 386                 return -EINVAL;
 387
 388         switch (cmd) {
 389         case I8K_BIOS_VERSION:
 390                 val = (bios_version[0] << 16) |
 391                                 (bios_version[1] << 8) | bios_version[2];
 392                 break;
 393
 394         case I8K_MACHINE_ID:
 395                 memset(buff, 0, 16);
 396                 strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
 397                         sizeof(buff));
 398                 break;
 399
 400         case I8K_FN_STATUS:
 401                 val = i8k_get_fn_status();
 402                 break;
 403
 404         case I8K_POWER_STATUS:
 405                 val = i8k_get_power_status();
 406                 break;
 407
 408         case I8K_GET_TEMP:
 409                 val = i8k_get_temp(0);
 410                 break;
 411
 412         case I8K_GET_SPEED:
 413                 if (copy_from_user(&val, argp, sizeof(int)))
 414                         return -EFAULT;
 415
 416                 val = i8k_get_fan_speed(val);
 417                 break;
 418
 419         case I8K_GET_FAN:
 420                 if (copy_from_user(&val, argp, sizeof(int)))
 421                         return -EFAULT;
 422
 423                 val = i8k_get_fan_status(val);
 424                 break;
 425
 426         case I8K_SET_FAN:
 427                 if (restricted && !capable(CAP_SYS_ADMIN))
 428                         return -EPERM;
 429
 430                 if (copy_from_user(&val, argp, sizeof(int)))
 431                         return -EFAULT;
 432
 433                 if (copy_from_user(&speed, argp + 1, sizeof(int)))
 434                         return -EFAULT;
 435
 436                 val = i8k_set_fan(val, speed);
 437                 break;
 438
 439         default:
 440                 return -EINVAL;
 441         }
 442
 443         if (val < 0)
 444                 return val;
 445
 446         switch (cmd) {
 447         case I8K_BIOS_VERSION:
 448                 if (copy_to_user(argp, &val, 4))
 449                         return -EFAULT;
 450
 451                 break;
 452         case I8K_MACHINE_ID:
 453                 if (copy_to_user(argp, buff, 16))
 454                         return -EFAULT;
 455
 456                 break;
 457         default:
 458                 if (copy_to_user(argp, &val, sizeof(int)))
 459                         return -EFAULT;
 460
 461                 break;
 462         }
 463
 464         return 0;
 465 }
 466
 467 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 468 {
 469         long ret;
 470
 471         mutex_lock(&i8k_mutex);
 472         ret = i8k_ioctl_unlocked(fp, cmd, arg);
 473         mutex_unlock(&i8k_mutex);
 474
 475         return ret;
 476 }
 477
 478 /*
 479  * Print the information for /proc/i8k.
 480  */
 481 static int i8k_proc_show(struct seq_file *seq, void *offset)
 482 {
 483         int fn_key, cpu_temp, ac_power;
 484         int left_fan, right_fan, left_speed, right_speed;
 485
 486         cpu_temp        = i8k_get_temp(0);                      /* 11100 µs */
 487         left_fan        = i8k_get_fan_status(I8K_FAN_LEFT);     /*   580 µs */
 488         right_fan       = i8k_get_fan_status(I8K_FAN_RIGHT);    /*   580 µs */
 489         left_speed      = i8k_get_fan_speed(I8K_FAN_LEFT);      /*   580 µs */
 490         right_speed     = i8k_get_fan_speed(I8K_FAN_RIGHT);     /*   580 µs */
 491         fn_key          = i8k_get_fn_status();                  /*   750 µs */
 492         if (power_status)
 493                 ac_power = i8k_get_power_status();              /* 14700 µs */
 494         else
 495                 ac_power = -1;
 496
 497         /*
 498          * Info:
 499          *
 500          * 1)  Format version (this will change if format changes)
 501          * 2)  BIOS version
 502          * 3)  BIOS machine ID
 503          * 4)  Cpu temperature
 504          * 5)  Left fan status
 505          * 6)  Right fan status
 506          * 7)  Left fan speed
 507          * 8)  Right fan speed
 508          * 9)  AC power
 509          * 10) Fn Key status
 510          */
 511         seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
 512                    I8K_PROC_FMT,
 513                    bios_version,
 514                    i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
 515                    cpu_temp,
 516                    left_fan, right_fan, left_speed, right_speed,
 517                    ac_power, fn_key);
 518
 519         return 0;
 520 }
 521
 522 static int i8k_open_fs(struct inode *inode, struct file *file)
 523 {
 524         return single_open(file, i8k_proc_show, NULL);
 525 }
 526
 527 static const struct file_operations i8k_fops = {
 528         .owner          = THIS_MODULE,
 529         .open           = i8k_open_fs,
 530         .read           = seq_read,
 531         .llseek         = seq_lseek,
 532         .release        = single_release,
 533         .unlocked_ioctl = i8k_ioctl,
 534 };
 535
 536 static void __init i8k_init_procfs(void)
 537 {
 538         /* Register the proc entry */
 539         proc_create("i8k", 0, NULL, &i8k_fops);
 540 }
 541
 542 static void __exit i8k_exit_procfs(void)
 543 {
 544         remove_proc_entry("i8k", NULL);
 545 }
 546
 547 #else
 548
 549 static inline void __init i8k_init_procfs(void)
 550 {
 551 }
 552
 553 static inline void __exit i8k_exit_procfs(void)
 554 {
 555 }
 556
 557 #endif
 558
 559 /*
 560  * Hwmon interface
 561  */
 562
 563 static ssize_t i8k_hwmon_show_temp_label(struct device *dev,
 564                                          struct device_attribute *devattr,
 565                                          char *buf)
 566 {
 567         static const char * const labels[] = {
 568                 "CPU",
 569                 "GPU",
 570                 "SODIMM",
 571                 "Other",
 572                 "Ambient",
 573                 "Other",
 574         };
 575         int index = to_sensor_dev_attr(devattr)->index;
 576         int type;
 577
 578         type = i8k_get_temp_type(index);
 579         if (type < 0)
 580                 return type;
 581         if (type >= ARRAY_SIZE(labels))
 582                 type = ARRAY_SIZE(labels) - 1;
 583         return sprintf(buf, "%s\n", labels[type]);
 584 }
 585
 586 static ssize_t i8k_hwmon_show_temp(struct device *dev,
 587                                    struct device_attribute *devattr,
 588                                    char *buf)
 589 {
 590         int index = to_sensor_dev_attr(devattr)->index;
 591         int temp;
 592
 593         temp = i8k_get_temp(index);
 594         if (temp < 0)
 595                 return temp;
 596         return sprintf(buf, "%d\n", temp * 1000);
 597 }
 598
 599 static ssize_t i8k_hwmon_show_fan_label(struct device *dev,
 600                                         struct device_attribute *devattr,
 601                                         char *buf)
 602 {
 603         static const char * const labels[] = {
 604                 "Processor Fan",
 605                 "Motherboard Fan",
 606                 "Video Fan",
 607                 "Power Supply Fan",
 608                 "Chipset Fan",
 609                 "Other Fan",
 610         };
 611         int index = to_sensor_dev_attr(devattr)->index;
 612         bool dock = false;
 613         int type;
 614
 615         type = i8k_get_fan_type(index);
 616         if (type < 0)
 617                 return type;
 618
 619         if (type & 0x10) {
 620                 dock = true;
 621                 type &= 0x0F;
 622         }
 623
 624         if (type >= ARRAY_SIZE(labels))
 625                 type = (ARRAY_SIZE(labels) - 1);
 626
 627         return sprintf(buf, "%s%s\n", (dock ? "Docking " : ""), labels[type]);
 628 }
 629
 630 static ssize_t i8k_hwmon_show_fan(struct device *dev,
 631                                   struct device_attribute *devattr,
 632                                   char *buf)
 633 {
 634         int index = to_sensor_dev_attr(devattr)->index;
 635         int fan_speed;
 636
 637         fan_speed = i8k_get_fan_speed(index);
 638         if (fan_speed < 0)
 639                 return fan_speed;
 640         return sprintf(buf, "%d\n", fan_speed);
 641 }
 642
 643 static ssize_t i8k_hwmon_show_pwm(struct device *dev,
 644                                   struct device_attribute *devattr,
 645                                   char *buf)
 646 {
 647         int index = to_sensor_dev_attr(devattr)->index;
 648         int status;
 649
 650         status = i8k_get_fan_status(index);
 651         if (status < 0)
 652                 return -EIO;
 653         return sprintf(buf, "%d\n", clamp_val(status * i8k_pwm_mult, 0, 255));
 654 }
 655
 656 static ssize_t i8k_hwmon_set_pwm(struct device *dev,
 657                                  struct device_attribute *attr,
 658                                  const char *buf, size_t count)
 659 {
 660         int index = to_sensor_dev_attr(attr)->index;
 661         unsigned long val;
 662         int err;
 663
 664         err = kstrtoul(buf, 10, &val);
 665         if (err)
 666                 return err;
 667         val = clamp_val(DIV_ROUND_CLOSEST(val, i8k_pwm_mult), 0, i8k_fan_max);
 668
 669         mutex_lock(&i8k_mutex);
 670         err = i8k_set_fan(index, val);
 671         mutex_unlock(&i8k_mutex);
 672
 673         return err < 0 ? -EIO : count;
 674 }
 675
 676 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 0);
 677 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 678                           0);
 679 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 1);
 680 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 681                           1);
 682 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 2);
 683 static SENSOR_DEVICE_ATTR(temp3_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 684                           2);
 685 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 3);
 686 static SENSOR_DEVICE_ATTR(temp4_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 687                           3);
 688 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL, 0);
 689 static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
 690                           0);
 691 static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
 692                           i8k_hwmon_set_pwm, 0);
 693 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
 694                           1);
 695 static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
 696                           1);
 697 static SENSOR_DEVICE_ATTR(pwm2, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
 698                           i8k_hwmon_set_pwm, 1);
 699
 700 static struct attribute *i8k_attrs[] = {
 701         &sensor_dev_attr_temp1_input.dev_attr.attr,     /* 0 */
 702         &sensor_dev_attr_temp1_label.dev_attr.attr,     /* 1 */
 703         &sensor_dev_attr_temp2_input.dev_attr.attr,     /* 2 */
 704         &sensor_dev_attr_temp2_label.dev_attr.attr,     /* 3 */
 705         &sensor_dev_attr_temp3_input.dev_attr.attr,     /* 4 */
 706         &sensor_dev_attr_temp3_label.dev_attr.attr,     /* 5 */
 707         &sensor_dev_attr_temp4_input.dev_attr.attr,     /* 6 */
 708         &sensor_dev_attr_temp4_label.dev_attr.attr,     /* 7 */
 709         &sensor_dev_attr_fan1_input.dev_attr.attr,      /* 8 */
 710         &sensor_dev_attr_fan1_label.dev_attr.attr,      /* 9 */
 711         &sensor_dev_attr_pwm1.dev_attr.attr,            /* 10 */
 712         &sensor_dev_attr_fan2_input.dev_attr.attr,      /* 11 */
 713         &sensor_dev_attr_fan2_label.dev_attr.attr,      /* 12 */
 714         &sensor_dev_attr_pwm2.dev_attr.attr,            /* 13 */
 715         NULL
 716 };
 717
 718 static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
 719                               int index)
 720 {
 721         if (index >= 0 && index <= 1 &&
 722             !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
 723                 return 0;
 724         if (index >= 2 && index <= 3 &&
 725             !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP2))
 726                 return 0;
 727         if (index >= 4 && index <= 5 &&
 728             !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP3))
 729                 return 0;
 730         if (index >= 6 && index <= 7 &&
 731             !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP4))
 732                 return 0;
 733         if (index >= 8 && index <= 10 &&
 734             !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN1))
 735                 return 0;
 736         if (index >= 11 && index <= 13 &&
 737             !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
 738                 return 0;
 739
 740         return attr->mode;
 741 }
 742
 743 static const struct attribute_group i8k_group = {
 744         .attrs = i8k_attrs,
 745         .is_visible = i8k_is_visible,
 746 };
 747 __ATTRIBUTE_GROUPS(i8k);
 748
 749 static int __init i8k_init_hwmon(void)
 750 {
 751         int err;
 752
 753         i8k_hwmon_flags = 0;
 754
 755         /* CPU temperature attributes, if temperature type is OK */
 756         err = i8k_get_temp_type(0);
 757         if (err >= 0)
 758                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;
 759         /* check for additional temperature sensors */
 760         err = i8k_get_temp_type(1);
 761         if (err >= 0)
 762                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2;
 763         err = i8k_get_temp_type(2);
 764         if (err >= 0)
 765                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3;
 766         err = i8k_get_temp_type(3);
 767         if (err >= 0)
 768                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
 769
 770         /* First fan attributes, if fan type is OK */
 771         err = i8k_get_fan_type(0);
 772         if (err >= 0)
 773                 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
 774
 775         /* Second fan attributes, if fan type is OK */
 776         err = i8k_get_fan_type(1);
 777         if (err >= 0)
 778                 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
 779
 780         i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "dell_smm",
 781                                                           NULL, i8k_groups);
 782         if (IS_ERR(i8k_hwmon_dev)) {
 783                 err = PTR_ERR(i8k_hwmon_dev);
 784                 i8k_hwmon_dev = NULL;
 785                 pr_err("hwmon registration failed (%d)\n", err);
 786                 return err;
 787         }
 788         return 0;
 789 }
 790
 791 struct i8k_config_data {
 792         uint fan_mult;
 793         uint fan_max;
 794 };
 795
 796 enum i8k_configs {
 797         DELL_LATITUDE_D520,
 798         DELL_PRECISION_490,
 799         DELL_STUDIO,
 800         DELL_XPS,
 801 };
 802
 803 static const struct i8k_config_data i8k_config_data[] = {
 804         [DELL_LATITUDE_D520] = {
 805                 .fan_mult = 1,
 806                 .fan_max = I8K_FAN_TURBO,
 807         },
 808         [DELL_PRECISION_490] = {
 809                 .fan_mult = 1,
 810                 .fan_max = I8K_FAN_TURBO,
 811         },
 812         [DELL_STUDIO] = {
 813                 .fan_mult = 1,
 814                 .fan_max = I8K_FAN_HIGH,
 815         },
 816         [DELL_XPS] = {
 817                 .fan_mult = 1,
 818                 .fan_max = I8K_FAN_HIGH,
 819         },
 820 };
 821
 822 static struct dmi_system_id i8k_dmi_table[] __initdata = {
 823         {
 824                 .ident = "Dell Inspiron",
 825                 .matches = {
 826                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
 827                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
 828                 },
 829         },
 830         {
 831                 .ident = "Dell Latitude",
 832                 .matches = {
 833                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
 834                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
 835                 },
 836         },
 837         {
 838                 .ident = "Dell Inspiron 2",
 839                 .matches = {
 840                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 841                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
 842                 },
 843         },
 844         {
 845                 .ident = "Dell Latitude D520",
 846                 .matches = {
 847                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 848                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
 849                 },
 850                 .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
 851         },
 852         {
 853                 .ident = "Dell Latitude 2",
 854                 .matches = {
 855                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 856                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
 857                 },
 858         },
 859         {       /* UK Inspiron 6400  */
 860                 .ident = "Dell Inspiron 3",
 861                 .matches = {
 862                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 863                         DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
 864                 },
 865         },
 866         {
 867                 .ident = "Dell Inspiron 3",
 868                 .matches = {
 869                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 870                         DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
 871                 },
 872         },
 873         {
 874                 .ident = "Dell Precision 490",
 875                 .matches = {
 876                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 877                         DMI_MATCH(DMI_PRODUCT_NAME,
 878                                   "Precision WorkStation 490"),
 879                 },
 880                 .driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
 881         },
 882         {
 883                 .ident = "Dell Precision",
 884                 .matches = {
 885                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 886                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
 887                 },
 888         },
 889         {
 890                 .ident = "Dell Vostro",
 891                 .matches = {
 892                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 893                         DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
 894                 },
 895         },
 896         {
 897                 .ident = "Dell XPS421",
 898                 .matches = {
 899                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 900                         DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
 901                 },
 902         },
 903         {
 904                 .ident = "Dell Studio",
 905                 .matches = {
 906                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 907                         DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
 908                 },
 909                 .driver_data = (void *)&i8k_config_data[DELL_STUDIO],
 910         },
 911         {
 912                 .ident = "Dell XPS 13",
 913                 .matches = {
 914                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 915                         DMI_MATCH(DMI_PRODUCT_NAME, "XPS13"),
 916                 },
 917                 .driver_data = (void *)&i8k_config_data[DELL_XPS],
 918         },
 919         {
 920                 .ident = "Dell XPS M140",
 921                 .matches = {
 922                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 923                         DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
 924                 },
 925                 .driver_data = (void *)&i8k_config_data[DELL_XPS],
 926         },
 927         { }
 928 };
 929
 930 MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
 931
 932 static struct dmi_system_id i8k_blacklist_dmi_table[] __initdata = {
 933         {
 934                 /*
 935                  * CPU fan speed going up and down on Dell Studio XPS 8000
 936                  * for unknown reasons.
 937                  */
 938                 .ident = "Dell Studio XPS 8000",
 939                 .matches = {
 940                         DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 941                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8000"),
 942                 },
 943         },
 944         {
 945                 /*
 946                  * CPU fan speed going up and down on Dell Studio XPS 8100
 947                  * for unknown reasons.
 948                  */
 949                 .ident = "Dell Studio XPS 8100",
 950                 .matches = {
 951                         DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 952                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
 953                 },
 954         },
 955         { }
 956 };
 957
 958 /*
 959  * Probe for the presence of a supported laptop.
 960  */
 961 static int __init i8k_probe(void)
 962 {
 963         const struct dmi_system_id *id;
 964         int fan, ret;
 965
 966         /*
 967          * Get DMI information
 968          */
 969         if (!dmi_check_system(i8k_dmi_table) ||
 970             dmi_check_system(i8k_blacklist_dmi_table)) {
 971                 if (!ignore_dmi && !force)
 972                         return -ENODEV;
 973
 974                 pr_info("not running on a supported Dell system.\n");
 975                 pr_info("vendor=%s, model=%s, version=%s\n",
 976                         i8k_get_dmi_data(DMI_SYS_VENDOR),
 977                         i8k_get_dmi_data(DMI_PRODUCT_NAME),
 978                         i8k_get_dmi_data(DMI_BIOS_VERSION));
 979         }
 980
 981         strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
 982                 sizeof(bios_version));
 983
 984         /*
 985          * Get SMM Dell signature
 986          */
 987         if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
 988             i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
 989                 pr_err("unable to get SMM Dell signature\n");
 990                 if (!force)
 991                         return -ENODEV;
 992         }
 993
 994         /*
 995          * Set fan multiplier and maximal fan speed from dmi config
 996          * Values specified in module parameters override values from dmi
 997          */
 998         id = dmi_first_match(i8k_dmi_table);
 999         if (id && id->driver_data) {
1000                 const struct i8k_config_data *conf = id->driver_data;
1001                 if (!fan_mult && conf->fan_mult)
1002                         fan_mult = conf->fan_mult;
1003                 if (!fan_max && conf->fan_max)
1004                         fan_max = conf->fan_max;
1005         }
1006
1007         i8k_fan_max = fan_max ? : I8K_FAN_HIGH; /* Must not be 0 */
1008         i8k_pwm_mult = DIV_ROUND_UP(255, i8k_fan_max);
1009
1010         if (!fan_mult) {
1011                 /*
1012                  * Autodetect fan multiplier based on nominal rpm
1013                  * If fan reports rpm value too high then set multiplier to 1
1014                  */
1015                 for (fan = 0; fan < 2; ++fan) {
1016                         ret = i8k_get_fan_nominal_speed(fan, i8k_fan_max);
1017                         if (ret < 0)
1018                                 continue;
1019                         if (ret > I8K_FAN_MAX_RPM)
1020                                 i8k_fan_mult = 1;
1021                         break;
1022                 }
1023         } else {
1024                 /* Fan multiplier was specified in module param or in dmi */
1025                 i8k_fan_mult = fan_mult;
1026         }
1027
1028         return 0;
1029 }
1030
1031 static int __init i8k_init(void)
1032 {
1033         int err;
1034
1035         /* Are we running on an supported laptop? */
1036         if (i8k_probe())
1037                 return -ENODEV;
1038
1039         err = i8k_init_hwmon();
1040         if (err)
1041                 return err;
1042
1043         i8k_init_procfs();
1044         return 0;
1045 }
1046
1047 static void __exit i8k_exit(void)
1048 {
1049         hwmon_device_unregister(i8k_hwmon_dev);
1050         i8k_exit_procfs();
1051 }
1052
1053 module_init(i8k_init);
1054 module_exit(i8k_exit);